Transmissions and DrivetrainNeed help with your trans? Problems with your axle?
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I have a 1989 Trans Am GTA with a 5.7L TPI and 700R4 tranny. I bought this car a couple of months ago and had to do a bunch of work to it and finally got it on the road for the first time last night. For some reason the car will not grab 3rd gear. Instead of shifting into third it drops right out like it's in neutral. The only thing I've done transmissionwise is replace the kickdown cable. I've tried to do the adjustment proceedure but it makes no difference. Any ideas would be greatly appreciated. TIA
As a side note, when I try to do the kickdown cable adjustment it never "clicks" as I turn the throttle. When I get the throttle to about the 3/4 position the slider just pops out from the adjustment position with kind of a springy poing sound. Is this what it is supposed to do?
That's a classic 3/4 clutch failure. Probably the weakest part of the 700R4.
My experience is that once that happens, there's no adjustment to bring it back.
As far as the TV cable goes, if you're getting some action during the OEM set up procedure, then you probably have it adjusted correctly.
Double check your cable and make sure its the right one. Also double check that its properly hooked into the transmission housing. If you did the adjustment right you should here a loud click sound. Here is a good link http://www.tciauto.com/Products/Inst...ble_adjust.htm
Also check your fluid for color and debris.
I bet you changed the trans fluid right. Ive noticed that if the trans hasnt had it done regularly its best to leave it alone. happened to me with a turbo 350 in a cutlass and the 700r4 in my iroc
yes the band may be bad, but it is a 2-4 band. The 3-4 clutches usually cause the engine revv into third shift but a lot of times it also causes the band to burn also. It can also go the other direction with the band taking out the 3-4's so it's a lose lose. If the trans try's to make the shift (it did because the engine revved) and it has the 1-2 shift you could reasonably figure that the 3-4 clutches are bad. You could always put a pressure gauge on the port to check the hydraulic ability of the oil circuit which will give a good pressure reading in that gear but the clutches just won't hold. The third oil circuit is on the passenger side aft of the servo cover and above the fourth oil. it is a pipe plug. you should see anywhere from 56-75psi at idle in manual third while the car is sitting still.
Thanks all for the ideas. I've taken the transmission out of the car and my bother-in-law the mechanic has graciously volunteered to rebuild it for me. I will post an update when I get it back in the car.
yes the band may be bad, but it is a 2-4 band. The 3-4 clutches usually cause the engine revv into third shift but a lot of times it also causes the band to burn also. It can also go the other direction with the band taking out the 3-4's so it's a lose lose. If the trans try's to make the shift (it did because the engine revved) and it has the 1-2 shift you could reasonably figure that the 3-4 clutches are bad. You could always put a pressure gauge on the port to check the hydraulic ability of the oil circuit which will give a good pressure reading in that gear but the clutches just won't hold. The third oil circuit is on the passenger side aft of the servo cover and above the fourth oil. it is a pipe plug. you should see anywhere from 56-75psi at idle in manual third while the car is sitting still.
true true but the tranny still needs a o/h check for any debrei in the oil pan,any signs of metal you shold replace the tranny and not rebuild,clutch material(blackish grey material) is normal and can rebuild.
So we got the trans rebuilt and back into the car. I now have 3rd gear but the trans does not want to shift into overdrive. When we first got the trans in the car and fluid in it we ran it on jack stands and it seemed to go into OD and the converter locked up but then it stuck in lockup so the car would stall in reverse. We unhooked the solenoid connector and got it working again so we plugged it back in but now it has no OD. any ideas? TIA
I bet you changed the trans fluid right. Ive noticed that if the trans hasnt had it done regularly its best to leave it alone. happened to me with a turbo 350 in a cutlass and the 700r4 in my iroc
I went to aamco to get my trans serviced once and they said they were hesitant in changing the fluid if it has been along time since its last service. for some reason the new fluid will cause leaks complete failure of the trans in some cases. they told me they had to due a few tests on it to make sure it would survive the fluid change...
The lockup issue turned out to be a cocked brake switch that wasn't allowing the plunger to extend. Repositioned the switch and all is well.
Also, finally got Overdrive. I took it out to get gas and after about 4 miles it finally dropped into overdrive and now it works fine. I think it must have been a spot of gunk or assembly lube blocking a channel somewhere and finally worked itself loose or the fluid just hadn't worked itself fully into the system. I check the fluid when I got home because it seemed to slip a little changing gears and it was almost 2 full quarts low! Whatever the blockage or airbubble was in there was blocking quite a bit. I'm just glad to finally have it back in full working condition. Thanks to all for your comments and suggestions. Til next time...
